Super-hydrophobic cotton fabric and preparation method thereof

Abstract

The invention relates to a super-hydrophobic cotton fabric and a preparation method thereof. The fabric can be prepared by adopting the following method: firstly, carrying out oxidation treatment on a cotton fabric; secondly, graphene oxide is subjected to chemical modification, and a graphene oxide modified product containing dichloro-s-triazine is prepared; finally, the graphene oxide modified product reacts with the cotton fabric, and the super-hydrophobic cotton fabric is prepared. The surface of the prepared super-hydrophobic cotton fabric contains graphene, the apparent contact angle range of water drops on the cotton fabric ranges from 152 degrees to 156 degrees, and the super-hydrophobic cotton fabric shows good super-hydrophobicity; after the cotton fabric is washed for 10 times, the hydrophobic property of the cotton fabric is still not obviously weakened.

Description

Technical Field

[0001] The present invention belongs to the technical field of fabric preparation, and particularly relates to a superhydrophobic cotton fabric and a preparation method thereof. Background Art

[0002] A large amount of detergents are required for washing textiles. Most detergents are synthetic organic compounds, such as washing powder and dishwashing liquid. They contain a relatively high amount of phosphorus (sodium phosphate). After washing, the phosphorus-containing wastewater flows into rivers, lakes and seas, causing eutrophication of water bodies. As a result, algae in the water bodies multiply vigorously, causing fish and other aquatic organisms to die of hypoxia until the water quality deteriorates and even becomes smelly. In addition, detergents have a direct irritating effect on the skin and can cause various skin diseases. Therefore, fabrics with superhydrophobic functions have important application values in aspects such as waterproofing, anti-pollution and self-cleaning.

[0003] Due to its unique softness, breathability, warmth retention, comfort and biodegradability, cotton fabrics are widely used in daily life. In recent years, more and more researchers have been interested in endowing fabrics with functions such as self-cleaning, antibacterial, anti-pollution and water-oil separation through surface hydrophobic modification of fabrics.

[0004] Literature research shows that the superhydrophobic performance of cotton fabrics has received extensive attention. For example, Chinese Patent Application No. 202011225659.9 discloses a method for superhydrophobic modification of waste cotton fabrics using polyphenols: selecting waste cotton fabrics as the substrate material, reusing them while reducing environmental pressure, treating the waste cotton fabrics with dopamine and long-chain alkylamines, and directly carrying out modification without decolorization and other treatments. The micro-nano structure is constructed on the surface of the waste cotton fabric by polyphenols to increase the surface roughness, and then the surface energy of the waste cotton fabric is reduced by long-chain alkylamines, thus finally obtaining superhydrophobic waste cotton fabrics; Chinese Patent Application No. 202010312644.X discloses a superhydrophobic cotton fiber textile and a preparation method thereof: using cotton fiber fabrics as the substrate, constructing a micro-nano rough structure on the fiber surface by treating the fiber with a mixed acid; then, covalently grafting long-chain alkanes with low surface energy onto the surface of cotton fibers through the reaction activity of isocyanate groups and active hydrogen groups to obtain superhydrophobic cotton fiber fabrics with stable properties.

[0005] At present, the raw materials used for superhydrophobic surfaces are expensive, the preparation process is complex, the durability of superhydrophobic surfaces is poor, or a large amount of low surface energy substances such as organic fluorides are used to modify superhydrophobic surfaces, thus limiting their wide application in industrial production. Therefore, it is urgent to improve the existing technology and develop a simple, environmentally friendly and inexpensive method for manufacturing superhydrophobic cotton fabrics. Summary of the Invention

[0006] Aiming at the above-mentioned drawbacks in the prior art, the purpose of the present invention is to provide a superhydrophobic cotton fabric and a preparation method thereof.

[0007] The purpose of the present invention is to provide a superhydrophobic cotton fabric, which has the characteristics of superhydrophobicity, antibacterial property, environmental protection, etc.; the fabric can be prepared by the following method: First, the cotton fabric is subjected to oxidation treatment; second, graphene oxide is chemically modified to obtain a graphene oxide modified product containing dichlorotriazine; finally, the graphene oxide modified product reacts with the cotton fabric to obtain a superhydrophobic cotton fabric.

[0008] The purpose of the present invention is achieved by the following technical solutions:

[0009] A preparation method of a superhydrophobic cotton fabric, comprising the following steps:

[0010] (1) Oxidation treatment of the cotton fabric: The cotton fabric is placed in a mixed solution containing hydrogen peroxide and tap water and treated at room temperature for 5 to 15 minutes.

[0011] Preferably, the dosage ratio of hydrogen peroxide, cotton fabric and tap water is 1 mL∶(10 - 20) g∶(100 - 200) mL.

[0012] (2) Chemical modification of graphene oxide: Under ice bath conditions, graphene oxide is added to a three-necked flask containing tetrahydrofuran to obtain a mixed solution a, cyanuric chloride and potassium bicarbonate are dissolved in tetrahydrofuran to obtain a mixed solution b, then the mixed solution b is added dropwise to the mixed solution a, and after the addition is complete, stirring reaction continues. The tetrahydrofuran solvent in the reaction solution is removed by a rotary evaporator, the reaction product is washed with deionized water multiple times, and finally the product is dried to obtain a graphene oxide modified product.

[0013] Preferably, the dosage ratio of graphene oxide and tetrahydrofuran in the mixed solution a is 1 g∶(100 - 200) mL; the dosage ratio of cyanuric chloride, potassium bicarbonate and tetrahydrofuran in the mixed solution b is 1 g∶(0.1 - 0.3) g∶(100 - 200) mL.

[0014] Preferably, the dropping time is 1 to 3 h, and the stirring reaction time after the addition is complete is 2 to 3 h.

[0015] Preferably, the drying conditions are: vacuum drying, drying time 10 to 20 h, drying temperature 30 to 50 °C.

[0016] (3) Hydrophobic finishing of the cotton fabric: The cotton fabric and the graphene oxide modified product are placed in tap water for reaction. First, sodium chloride is added and reacted at room temperature for 20 min; then sodium carbonate is added, the temperature is raised to 60 °C, and the reaction is carried out for 1 h. Finally, it is washed with water and dried.

[0017] Preferably, the dosage ratio of the cotton fabric, the graphene oxide modified product and tap water is 1 g∶(0.01 - 0.03) g∶(100 - 200) mL.

[0018] Preferably, the mass fraction of the sodium chloride in tap water is 2 - 4%; the mass fraction of the sodium carbonate in tap water is 1 - 2%.

[0019] Analysis of the reaction mechanism of the present invention: The molecular structure of graphene oxide is shown in the following chemical formula. It can be seen from the chemical formula that it contains more hydroxyl groups. Cyanuric chloride undergoes a substitution reaction with the hydroxyl groups of graphene oxide to form a graphene oxide modified product containing dichlorotriazine; this modified product has the characteristic groups of reactive dyes and has strong chemical reaction activity with cotton fibers; finally, graphene is grafted onto the surface of the cotton fabric, achieving an improvement in the hydrophobicity of the cotton fabric.

[0020]

[0021] The present invention has the following remarkable features:

[0022] (1) Graphene is a hydrophobic material, but it is very difficult to be applied to the fabric surface. The inventors of this application unexpectedly found that after chemical modification of graphene oxide, it is very easy to be grafted onto the surface of the cotton fabric, and the hydrophobicity of the surface of the cotton fabric grafted with graphene is significantly enhanced.

[0023] (2) The inventors of this application unexpectedly found that the oxidation treatment of the cotton fabric is beneficial to the reaction efficiency with the graphene oxide modified product containing dichlorotriazine, that is, it is beneficial to the improvement of the hydrophobicity of the cotton fabric.

[0024] (3) The superhydrophobic cotton fabric prepared by the present invention contains graphene on its surface, and the apparent contact angle of water droplets on the cotton fabric ranges between 152° and 156°, showing good superhydrophobicity; after 10 times of washing, the hydrophobic performance of the cotton fabric has not been significantly weakened.

[0025] (4) After 10 times of washing, the superhydrophobic performance of the superhydrophobic cotton fabric prepared by the present invention has not been significantly weakened, which indicates that graphene is firmly attached to the surface of the cotton fabric.

[0026] (5) The raw materials of the superhydrophobic cotton fabric prepared by the present invention are widely sourced, and the preparation process is simple, having good market promotion prospects. Detailed Description of the Invention

[0027] The following examples and comparative examples illustrate the present invention in detail.

[0028] Example 1:

[0029] In this embodiment, a preparation method of a superhydrophobic cotton fabric, the preparation method includes the following steps:

[0030] (1) Oxidation treatment of the cotton fabric: Place 10 g of the cotton fabric in a mixed solution containing 1 mL of hydrogen peroxide and 150 mL of tap water and treat it at room temperature for 10 minutes.

[0031] (2) Chemical modification of graphene oxide: Under ice bath conditions, add 1 g of graphene oxide to a three-necked flask containing 150 mL of tetrahydrofuran to obtain a mixed solution a. Dissolve 1 g of cyanuric chloride and 0.2 g of potassium bicarbonate in 150 mL of tetrahydrofuran to obtain a mixed solution b. Then, add the mixed solution b dropwise to the mixed solution a, and the dropping time is 2 h. After the dropping is completed, continue to stir and react, and the continuous stirring reaction time is 2.5 h. Use a rotary evaporator to remove the tetrahydrofuran solvent in the reaction solution, wash the reaction product with deionized water multiple times, and finally vacuum dry the product. The drying time is 15 h and the drying temperature is 40 °C to obtain a graphene oxide modified product.

[0032] (3) Hydrophobic finishing of the cotton fabric: Place 10 g of the cotton fabric and 0.2 g of the graphene oxide modified product in 1500 mL of tap water and react. First, add sodium chloride with a mass fraction of 3% of the tap water, and react at room temperature for 20 min; then add sodium carbonate with a mass fraction of 1.5% of the tap water, heat up to 60 °C, and react for 1 h. Finally, wash with water and dry.

[0033] Example 2:

[0034] In this embodiment, a preparation method of a superhydrophobic cotton fabric, the preparation method includes the following steps:

[0035] (1) Oxidation treatment of the cotton fabric: Place 10 g of the cotton fabric in a mixed solution containing 1 mL of hydrogen peroxide and 100 mL of tap water and treat it at room temperature for 5 minutes.

[0036] (2) Chemical modification of graphene oxide: Under ice bath conditions, add 1 g of graphene oxide to a three-necked flask containing 100 mL of tetrahydrofuran to obtain a mixed solution a. Dissolve 1 g of cyanuric chloride and 0.1 g of potassium bicarbonate in 100 mL of tetrahydrofuran to obtain a mixed solution b. Then, add the mixed solution b dropwise to the mixed solution a, and the dropping time is 1 h. After the dropping is completed, continue to stir and react, and the continuous stirring reaction time is 2 h. Use a rotary evaporator to remove the tetrahydrofuran solvent in the reaction solution, wash the reaction product with deionized water multiple times, and finally vacuum dry the product. The drying time is 10 h and the drying temperature is 30 °C to obtain a graphene oxide modified product.

[0037] (3) Hydrophobic finishing of cotton fabric: React 10 g of cotton fabric and 0.1 g of the modified graphene oxide product in 1000 mL of tap water. First, add sodium chloride with a mass fraction of 2% based on the mass of tap water, and react at room temperature for 20 min; then add sodium carbonate with a mass fraction of 1% based on the mass of tap water, heat up to 60 °C, and react for 1 h. Finally, wash with water and dry.

[0038] Example 3:

[0039] In this example, a method for preparing a superhydrophobic cotton fabric, the preparation method includes the following steps:

[0040] (1) Oxidation treatment of cotton fabric: Place 20 g of cotton fabric in a mixed solution containing 1 mL of hydrogen peroxide and 200 mL of tap water, and treat at room temperature for 15 minutes.

[0041] (2) Chemical modification of graphene oxide: Under ice bath conditions, add 1 g of graphene oxide to a three-necked flask containing 200 mL of tetrahydrofuran to obtain a mixed solution a. Dissolve 1 g of cyanuric chloride and 0.3 g of potassium bicarbonate in 200 mL of tetrahydrofuran to obtain a mixed solution b. Then, add the mixed solution b dropwise to the mixed solution a, and the dropping time is 3 h. After the dropping is completed, continue to stir and react for 3 h. Use a rotary evaporator to remove the tetrahydrofuran solvent in the reaction solution, wash the reaction product with deionized water multiple times, and finally dry the product under vacuum. The drying time is 20 h, and the drying temperature is 50 °C to obtain the modified graphene oxide product.

[0042] (3) Hydrophobic finishing of cotton fabric: React 10 g of cotton fabric and 0.3 g of the modified graphene oxide product in 2000 mL of tap water. First, add sodium chloride with a mass fraction of 4% based on the mass of tap water, and react at room temperature for 20 min; then add sodium carbonate with a mass fraction of 2% based on the mass of tap water, heat up to 60 °C, and react for 1 h. Finally, wash with water and dry.

[0043] Comparative Example A

[0044] Taking Example 1 as a comparison, in this comparative example, the cotton fabric is not subjected to oxidation treatment, that is, step (1) is not implemented, and other preparation methods are implemented according to the preparation method of Example 1.

[0045] Comparative Example B

[0046] Taking Example 1 as a comparison, in this comparative example, the chemical modification conditions of graphene oxide are changed, that is, in step (2), "potassium bicarbonate" is changed to "sodium chloride", and other preparation methods are implemented according to the preparation method of Example 1.

[0047] Comparative Example C

[0048] Taking Example 1 as a comparison, in this comparative example, the amount of the graphene oxide modified product was reduced, that is: "0.2 g of the graphene oxide modified product" in step (3) was changed to "0.02 g of the graphene oxide modified product", and other preparation methods were carried out according to the preparation method of Example 1.

[0049] Superhydrophobic performance test:

[0050] To better detect the superhydrophobicity of the superhydrophobic cotton fabric prepared in the present invention, the superhydrophobic cotton fabrics a, b, c, d, e, and f prepared in the above specific Examples 1 to 3 and Comparative Examples A to C of the present invention were selected. An XG-CAMA1 basic contact angle tester was used to measure the apparent contact angle of water droplets on the surface of the superhydrophobic cotton fabric. The number of test samples was not less than 30, and the test average value was taken. The fabric to be tested was subjected to standard washing according to the washing method of the color fastness to washing tester GB / T 20944.1-2007, and the superhydrophobic performance of the initial sample and the sample after 10 washes was tested. The test results are shown in Table 1.

[0051] Table 1 Apparent contact angles of water droplets on the cotton fabrics a, b, c, d, e, and f prepared in Examples 1 to 3 and Comparative Examples A to C

[0052] Apparent contact angle (°) a b c d e f Unwashed 155.3 154.7 152.2 105.4 97.6 84.5 Washed 10 times 145.6 143.4 146.8 85.8 78.3 57.4

[0053] As can be seen from Table 1, when the cotton fabric was not washed with water, the apparent contact angles of water droplets on the cotton fabrics a, b, and c prepared in Examples 1 to 3 were in the range of 152° to 156°. After 10 washes with water, the hydrophobic properties of fabrics a, b, and c did not decrease significantly. Therefore, it can be considered that the cotton fabric prepared in the present invention has superhydrophobicity. The superhydrophobicity of the superhydrophobic cotton fabrics d, e, and f prepared in Comparative Examples A-C was significantly worse, which indicates that: the oxidation treatment of the cotton fabric, the chemical modification conditions of graphene oxide, and the amount of the graphene oxide modified product all have important effects on the superhydrophobic performance of the cotton fabric.

Claims

1. A preparation method of a superhydrophobic cotton fabric, characterized in that The preparation method comprises the following steps: (1) Oxidation treatment of cotton fabric: Place the cotton fabric in a mixed solution containing hydrogen peroxide and tap water and treat it at room temperature for 5 - 15 minutes. (2) Chemical modification of graphene oxide: Under ice bath conditions, add graphene oxide into a three-necked flask containing tetrahydrofuran to obtain a mixed solution a. Dissolve cyanuric chloride and potassium bicarbonate in tetrahydrofuran to get a mixed solution b. Then, add the mixed solution b dropwise to the mixed solution a. After the dropwise addition, continue stirring and reacting. Use a rotary evaporator to remove the tetrahydrofuran solvent in the reaction solution. Wash the reaction product with deionized water multiple times, and finally dry the product to obtain a graphene oxide modified product. (3) Hydrophobic finishing of cotton fabric: Place the cotton fabric and the graphene oxide modified product in tap water for reaction. First, add sodium chloride and react at room temperature for 20 min. Then, add sodium carbonate and raise the temperature to 60 °C and react for 1 h. Finally, wash with water and dry.

2. The preparation method of a superhydrophobic cotton fabric according to claim 1, wherein, In step (1), the dosage ratio of hydrogen peroxide, cotton fabric, and tap water is 1 mL∶(10 - 20) g∶(100 - 200) mL.

3. The preparation method of a superhydrophobic cotton fabric according to claim 1, characterized in that, In step (2), the dosage ratio of graphene oxide and tetrahydrofuran in the mixed solution a is 1 g∶(100 - 200) mL; the dosage ratio of cyanuric chloride, potassium bicarbonate, and tetrahydrofuran in the mixed solution b is 1 g∶(0.1 - 0.3) g∶(100 - 200) mL; the dropwise addition time is 1 - 3 h, and the stirring reaction time after the dropwise addition is 2 - 3 h; the drying conditions are: vacuum drying, drying time 10 - 20 h, drying temperature 30 - 50 °C.

4. The preparation method of a superhydrophobic cotton fabric according to claim 1, characterized in that, In step (3), the dosage ratio of cotton fabric, graphene oxide modified product, and tap water is 1 g∶(0.01 - 0.03) g∶(100 - 200) mL; the dosage of sodium chloride accounts for 2 - 4% of the mass of tap water; the dosage of sodium carbonate accounts for 1 - 2% of the mass of tap water.

5. A superhydrophobic cotton fabric, characterized in that, Prepared by the method described in any one of claims 1 - 4.

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